1. Field of the Invention
This invention relates to a method for extracting a program and an apparatus for extracting a program and in particular, is suitably applied to a method for extracting an upward compatible program that can be replaced for another program of a plurality of programs having the same contents, and to such an apparatus for extracting an upward compatible program that is mounted with this method.
2. Description of the Related Art
In currently-used analog broadcast and digital broadcast and in terrestrial digital broadcast scheduled to be started at the end of 2003, in addition to a program, information related to the program (meta data) is transmitted. The meta data is data such as the date and time of broadcast, channel information, and the title and genre of the program.
Further, meta data that is to be handled in server type broadcast being now standardized can handle more detailed information as compared with meta data used in currently-used BS digital broadcast and the like. The meta data in the server type broadcast includes not only information such as title and genre but also various information, e.g., credit information such as performers and staffs of program, and alarm information to show the degree of description of violence and sex.
The meta data is transmitted before actual broadcast and a typical function using the meta data receiving in advance is an electronic program guide (EPG). The electronic program guide is a function of displaying channel, broadcast time, and program title, which are meta data, on a screen and displays genres in different colors and by different marks, detailed information such as commentators and performers, and information for limiting the age of a viewer such as parental guidance, and selects the station of a selected program and records a program and makes a reservation of recording a program, thereby assisting a user's viewing and scheduling.
TVs, tuners, and recorders mounted with the electronic program guide and internet electronic program guides have come into common use. A function of retrieving a program related to a specific program (program of the next time and repeat of program) and making a reservation of recording the program is known, as a schedule assistance technology using an electronic program guide.
Further, a function using this meta data includes also a program recommendation function. The program recommendation function utilizing program-related information includes: a filter type recommendation function of having a user having registered the genres of favorite programs and the names of favorite talents and of recommending a program meeting the information of this user's taste; a learning type recommendation function of extracting the information of a user's taste from the meta data of programs that the user viewed or recorded in the past and from the information of a user's operation history and of recommending a program based on the information of the user's taste; and a recommendation function of a combination type of both of these functions.
However, in the schedule assistance utilizing the electronic program guide, it is information related to a mode in which the contents of the program are broadcast such as channel and the date and time of broadcast, and is not information related to the contents of the program that the user can know as information related to the related program. For this reason, even if there is difference in the information related to the contents of the program such as subtitle and sound language between the related programs, it is difficult for the user to notice the difference. In the program recommendation function, there is a case where the program that has been already viewed or recorded by the user is also recommended as a recommendation program. Further, even when the broadcast conditions are different from those of the last time (for example, the same movie was broadcast last time in standard broadcast dubbed in Japanese and is broadcast this time in high-definition bilingual broadcast), the user needs to find the difference consciously to judge which program is upward compatible and to decide the handling of a program scheduled to be broadcast and a pre-recorded program.